Pascal problem with double dimensional function

Hello, i'm pretty new in programming, but got to write a projeckt which makes diverse matrix. I've got a problem with function because can't declare double dimensional matrix. This is the code, can't figure out how to make it.

function detrm(matrix:Array[0..10,0..10] of real; k:integer):real;vars,det:real;b:array[0..25,0..25] of real;i,j,m,n,c:Integer;beginfor c:=0 to k do begin m:=0; n:=0; for i:=0 to k do begin for j:=0 to k do begin b[i,j]:=0; if (i<>0) and (j<>c) then begin b[m,n]:=matrix[i,j]; end; end; end; end;